Control valve means for fuel injection systems



Jan. 25, 1966 c c E JR 3,231,003

CONTROL VALVE MEANS FOR FUEL INJECTION SYSTEMS Filed March 6, 1964 FIG 4 4A F/6.3 w

ATTORNEYS l87 INVENTOR.

4 ALVA H. R/CHCREEK JR.

United States Patent 3,231,003 CONTROL VALVE MEANS FOR FUEL INJECTION SYSTEMS Alva H. Richcreek, Jr., P.0. Box 6161, Murray Hill Station, Jacksonville, Fla. Filed Mar. 6, 1964, Ser. No. 350,045 11 Claims. (Cl. 158-42.1)

This invention relates to control valve means for fuel injection systems and more particularly concerns an overload valve means for a diesel fuel injection system.

A general object of this invention is to provide an improved overload valve means for a diesel fuel injection system.

Truckers desiring to obtain greater speed with their trucks often clamp the fuel return line from the engine fuel rail to the fuel tank either by placing a clamp on the flexible return line or inconspicuously crimping the rigid return line, or otherwise restricting such return line. Such clamping normally is accomplished in such a manner that the maintenance mechanics are unable to discover that the return lines have been clamped although they are certain that the drivers have clamped such return lines. The normal fuel flow in the return line is back-up when the return line is clamped causing greater fuel pressure in the injector system which must either be consumed in the engine cylinders and/ or a portion of the excess fuel passes out the exhaust and/or a portion of the excess fuel seeps down the cylinder walls below the pistons into the oil pan thereby diluting the engine oil and causing bearing burn out, scoring of the liners and pistons and otherwise requiring complete engine overhaul. Further, upon clamping the return line, the engine idles fast which causes improper shifting of the transmission resulting in grinding of the gears and jerking of the load. The entire drive chain, including the transmission and differential, is placed under severe strain by such jerking or snatching of the load which may be partially overcome by riding the clutch, rid- .ing of the clutch necessitating replacement thereof at more frequent intervals. Furthermore, the brakes of a diesel truck wear out in a shorter period of time due to the fact that the engine is turning at increased r.p.m.s and the engine is unable to approach the idle condition until the excess fuel accumulated in the injectors is consumed. Specific objects of this invention are to substantially alleviate the aforementioned d'ifliculties, and to deter truckers from clamping, restricting or attempting to clamp or restrict the return line in a diesel fuel injection system.

A particular object of this invention is to provide an improved overload valve means interposed between the fuel feed line and the fuel return line which is compact in construction and not easily tampered with by the drivers desiring to increase the r.p.m.s of the engine.

A further particular object is the provision of an improved unitary overload valve means which is economically manufactured and installed, and efficient and durable in use.

The novel features which are believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following descriptiontaken in connection with the accompanying drawing, in which:

FIGURE 1 is a diagrammatic view of the overload valve means connected in the fuel injection system in accordance with the invention;

FIGURE 2 is an enlarged cross-sectional view of the overload valve means in FIGURE 1;

3,231,003 Patented Jan. 25, 1966 'ice FIGURE 4 is a cross-sectional view taken along line 44 of FIGURE 3.

Referring now more particularly to the drawings, the fuel injection system for a diesel engine is generally depicted at 10 and includes a fuel tank 11, filter 12, pump 13, and fuel feed line means designated at for connecting the pump 13 and filter 12 between the tank 11 and the fuel injectors (not shown) of engine 16. Feed line means 15 is seen to include conduit 17 connecting tank 11 to filter 12, conduits 18 and 19 connecting filter 12 to pump 13, and conduit 20 connecting pump 13 to fuel injector rail 21 for distributing the fuel to the injectors of engine 16.

A return fuel line means 25 includes a fuel return rail 26 connected by conduits 2'7 and 28 to tank 11. Normally, the fuel injector rail 21 and fuel return rail 26 are rigid steel lines together with their respective associated conduits 20 and 27. The other conduits 28, 17, 18 and 19 may, for example, be copper tubing and/or made from flexible material, conduit 28 being the subject of the clamping and/ or restricting by the drivers desiring to increase the engine r.p.m. without being detected by their superiors through discovery by the shop mechanic during maintenance of the trucks.

In conventional fuel injection systems for diesels, the flow of fuel is depicted by arrows 30 and 31 from tank 11 to fuel injector rail 21, and by arrows 32 and 33 from fuel return rail 26 back to tank 11. The fuel is delivered to the injectors by pump 13 at approximately 120 psi. and the fuel is returned to tank 11 by free flow at little or no pressure. When the conventional fuel return line is clamped or restricted the fuel in the return line and rail backs-up and increases the fuel pressure in the injectors thereby enriching the fuel and air mixture to be consumed. The r.p.m. of the engine is increased resulting in increase of pump pressure, resulting in greater pressure in the injectors, etc.

The overload valve means in accordance with this invention is depicted at 35 and is mounted to engine 16 by U-shaped strap 38 and bolts 39, strap 38 being connected to valve means housing by bolt 64 threadedly mounted therein. Valve means 35 is connected in the fuel flow of line means 15 between pump 13 and tank and filter 11 and 12 by conduits 17, 18 and 19. Valve means 35 comprises a valve assembly generally indicated at 36 and a valve actuating assembly generally indicated at 37, assemblies 36 and 37 preferably being combined as a unitary assembly, as hereinafter described.

The valve means 35 and components thereof are clearly understood by reference to FIGURES 2, 3 and 4 wherein a unitary elongated cylindrical housing 40 is provided with a longitudinal stepped bore 41 to receive an elongated valving element 42 slidingly disposed therein. Bore 41 is constructed by suitably drilling through housing end 43, bore 41 being of a predetermined diameter and terminating at end wall 49. A laterally extending bore 44 is provided through housing 40 adjacent its opposite end 45, and bore 44 opens outwardly at the upper and lower surfaces 46 and 47 of housing 40. A bore 48, having a smaller diameter than bore 41, is then drilled longitudinally through the end wall or shoulder 49 of bore 41 for communication between longitudinal bore 41 and lateral bore 44. Another bore 50 is drilled laterally and upwardly through the rear surface 47 of housing 40 and communicates at its inner end 51 with bore 41.

The outwardly opening ends 52 and 53 of bore 44, respectively the return inlet and return outlet for valve means 35, are tapped to receive therein respective couplers 54 and 55 connected to conduits 27 and 28 of fuel return line means 25. The outwardly opening end or feed inlet 56 of bore 50 is tapped to receive coupler 57 which is connected to conduit 18 of fuel feed line means 15. The outwardly opening end or feed outlet 58 of bore 41 is tapped and a coupler 59 is threadedly mounted therein, and the conduit 19 of feed line means 15 is internally threaded within coupler 59. It is understood that couplers 54, 55 and 57 may be substantially identical to coupler S9 or other well known types of couplers may be employed herein.

A yieldable means in the form of compression spring 60 is disposed within bore 41 between valve element end 61 and annular washer 62 which is juxtaposed to the inner end 63 of coupler 59. A sealing member 65, in the form of a neoprene plug or the like, is nested within cavity 66 in valve element end 67 and adapted to normally sealingly engage a needle valve seat 68 which is threadedly connected to the-tapped end 69 of bore 48.

A portion 75 of valve element 42 is indented between its ends 61 and 67 and forms an annular groove 70 communicating with bore end 51 when the sealing member 65 engages seat 68, as depicted in FIGURE 2. A plurality of laterally extending passages 71, 72, 73 and 74 extend through the bottom wall portion 90 defining annular groove 70 thus providing communicating passages between passageway 76, which is bored longitudinally into valve element end 61, and bore 50. Annular groove 70 and bore wall portion 79 define therebetweeu an annular chamber 80 for the reception thereinto of fuel from bore 50. With the valve element 42 in its inoperative position shown and sealing member 65 engaging seat 68, the normal flow of fuel is shown by arrow 77 entering bore 50 from conduit 18, into annular chamber 80, through passages '71, 72, 73 and 74, into passageway 76, through bore 41 and washer opening 81 and out coupler passageway 82 into conduit 19, as shown by arrow 83, and finally continuing to engine 16.

After the fuel passes into injector fuel rail 21, the excess fuel is returned through return fuel rail 26, through conduit 27, and through end 52 of lateral bore 44, as indicated by arrow 85. The flow of fuel continues through bore 44 and out end 53 into conduit 28, as illustrated by arrow 86, into tank 11. When conduit 28 is clamped or restricted, the pressure of the fuel within bore 44, bore 48, stepped passageway 87, which extends through valve seat 68, increases to a predetermined amount, for example, 30 p.s.i., and the valve element 42 is pressured to forcibly compress spring 60 whereby member 65 is disengaged from seat 68. Valve element 42 moves against spring 6%) until chamber 80 is moved out of alignment from its communication with bore 59 thereby substantially cutting off the fuel flow from tank 11 which causes engine 16 to stop. It is to be understood that valve element 42 may be designed to be somewhat leaky and/ or be provided with suitable porting to permit a small amount of fuel to be passed to the engine 16 while valve element 42 is operative in substantially preventing the normal fuel flow to enable engine 16 to idle rather than stop. When the back pressure within clamped return line or conduit 28 decreases below a predetermined pressure, for example, below 30 p.s.i., the compressed spring'60 moves valve element 42 to realign chamber 89 with bore 50 to re-establish the normal fuel flow therethrough. It is to be noted that the spring 60 may be replaced with lighter or heavier springs depending on the particular fuel injection system and the return line pressure desired to actuate the valve element for cutting off thefeed fuel flow.

To prevent occurrences, such as by-passing the valve and the like, couplers 54 may be welded to housing 40 and steel conduit 27 thereby preventing the driver from disconnecting couplers 54 and 55 and providing a by-pass line therebetween. Valve means 35 would not prevent a driver from crimping the steel conduit 27 and/ or fuel rail 26, but such a driver would be discharged from his employment when the mechanic, during maintenance, reports such permanent damage. Couplers 59 and 57 may also be welded to housing 40 to prevent internal tampering with the valve element 42 or providing a fuel feed by-pass around valve means 35.

While only a certain preferred embodiment of this invention has been shown and described by way of illustration, many modifications will occur to those skilled in the art and it is, therefore, desired that it be understood that it is intended in the appended claims to cover all such modifications as fall within the true spirit and scope of this invention.

What is claimedas new and what it is desired to secure by Letters Patent of the United States is:

1. In a fuel injection system for an engine having a fuel tank, a pump, engine injectors, feed line means connecting said pump to said tank and said injectors for delivering fuel from said tank to said injectors, return line means connected between the engine and said tank for returning excess fuel from said injectors, the improvement comprising an overload valve means connected to said return line means and said feed line means between said pump and tank, said valve means being operable to substantially terminate the fuel flow through said feed line means when the pressure in said return line means exceeds a predetermined amount.

2. In a fuel injection system for adiesel engine having injectors connected by a feed line means through a pump and to a fuel tank for supplying fuel thereto, said engine further having return line means for returning excess fuel from said injectors to said tank, the improvement comprising an overload valve means connected to said return line means and responsive to the pressure therein above a predetermined amount, said valve means being connected between said pump and tank to said feed line means for terminating the fuel flow therethrough when Said valve means responds to the pressure within said return line means. i

3. In a fuel injection system for an engine having a fuel tank, a pump, engine injectors, feed line means connecting said pump to said tank and said injectors for delivering fuel from said tank to said injectors, return line means connected between the engine and said tank for returning excess fuel from said injectors, the improvement comprising an overload valve means including a unitary housing having bores intersecting internally thereof, a valve element movably positioned within one'said bore, said other bore having outwardly opening ends connected to said return line means and constituting a return inlet and a return outlet for said valve means for the return of fuel therethrough, said valve means having a feed inlet and a feed outlet communicating with said one bore for the passage of fuel therethrough, means for normally maintaining said valve element inoperative to permit fuel to pass from said feed inlet through said one bore and out said feed outlet, said valve element being responsive to a predetermined pressure in said other bore through said intersection thereof for moving said valve element blockingly between said feed inlet and outlet thereby to substantially terminate the fuel flow therethrough.

4. In a fuel injection system for a diesel engine having injectors connected by a feed line means through a pump and to a fuel tank for supplying fuel thereto, said engine further having return line means for returning excess fuel from said injectors to said tank, the improvement comprising an overload valve means including a valve assembly and a valve actuating assembly, said valve actuating assembly being connected to said return line means, said valve assembly being connected between said pump and tank to said feed line means for substantially terminating the fuel flow therethrough upon actuation thereof by said valve actuating assembly, said valve actuating assembly cooperating with said valve assembly to actuate said valve assembly when the pressure within said return line means exceeds a predetermined amount.

5. In a fuel injection system for an engine having a fuel tank, a pump, engine injectors, feed line means connecting said pump to said tank and said injectors for delivering fuel from said tank to said injectors, return line means connected between the engine and said tank for returning excess fuel from said injectors, the improvement comprising an overload valve means including a unitary housing having bores intersecting internally thereof, a valve element movably positioned within one said bore, said other bore having ends opening outwardly of said housing and connected within said return line means and constituting a return inlet and a return outlet for said valve means for the return of fuel therethrough, said housing having a feed inlet and a feed outlet communicating with said one bore for the normal passage of fuel therethrough, yieldable means for maintaining said valve element inoperative to permit fuel to pass from said feed inlet through said one borer. and out said feed outlet, said valve element being responsive to a predetermined pressure in said other bore through said intersection thereof for moving said valve element against said yieldable means for substantially blocking the flow of fuel from said feed inlet to said feed outlet.

6. In a fuel injection system for an engine having a fuel tank, a pump, engine injectors, feed line means connecting said pump to said tank and said injectors for delivering fuel from said tank to said injectors, return line means connected between the engine and said tank for returning excess fuel from said injectors, the improvement comprising a fuel control valve including an elongated housing having a laterally extending bore therethrough and opening outwardly of said housing at a return line inlet end and a return line outlet end, said return line means being connected to said return line inlet end and said return line outlet end for the return of fuel therethrough, said housing having a longitudinal bore intersecting said lateral bore at one of its ends and opening outwardly of said housing at a feed line outlet end, said housing having another laterally extending bore intersecting said longitudinal bore at one of its ends between said ends of said longitudinal bore and opening outwardly of said housing at a feed inlet end, said feed line means being connected to said feed inlet end and said feed outlet end for the passage of normal fuel therethrough, .a valve element movably positioned within said longitudinal bore, yieldable means within said longitudinal bore for maintaining said valve element inoperative to permit fuel to pass from said feed inlet end and out said feed outlet end, said valve element being responsive to a predetermined pressure of the returned fuel in said lateral bore for moving said valve element against said yieldable means for substantially blocking the flow of fuel from said feed inlet end to said feed outlet end.

7. The fuel injection system as defined in claim 6 wherein said fuel control valve further comprises a valve seat positioned within said longitudinal bore adjacent said one end thereof, said valve element including a sealing member attached to one end of said valve element and adapted and arranged to sealingly engage said valve seat when the pressure of the returned fuel within said lateral bore is below said predetermined pressure.

8. The fuel injection system as defined in claim 6 wherein said valve element includes an indented portion between its ends forming a chamber with the wall of said longitudinal bore, said chamber being adapted to be in communication with said other lateral bore when the pressure of the returned fuel within said lateral bore is below said predetermined pressure, said valve element having a passageway extending into and terminating at one of its ends therewithin and the other end communicating with said longitudinal bore, said valve element having a passage communicating between said chamber and said 6 passageway, said feed fluid flow passing through said other lateral bore into said chamber and through said passage into said passageway and out said longitudinal bore through said feed line outlet end, said chamber being out of alignment with said other lateral bore when said valve element responds to said predetermined pressure.

9. In a fuel injection system for an engine having a fuel tank, a pump, engine injectors, feed line means connecting said pump to said tank and said injectors for delivering fuel from said tank to said injectors, return line means connected between the engine and said tank for returning excess fuel from said injectors, the improvement comprising a fuel control valve including an elongated housing having a laterally extending bore therethrough and opening outwardly of said housing at a return line inlet end and a return line outlet end, said return line means being connected to said return line inlet end and said return line outlet end for the return of fuel therethrough, said housing having a longitudinal bore intersecting said lateral bore at one of its ends and opening outwardly of said housing at a feed line outlet end, a valve seat positioned within said longitudinal bore adjacent said one end thereof, said housing having another laterally extending bore intersecting said longitudinal bore at one of its ends between said ends of said longitudinal bore and opening outwardly of said housing at a feed inlet end, said feed line means being connected to said feed inlet end and said feed outlet end for the passage of normal fuel therethrough, a valve element movably positioned within said longitudinal bore and having an end portion adjacent said one end of said longitudinal bore, a sealing member attached to said one valve element end portion, yieldable means within said longitudinal bore for maintaining said valve element inoperative with said sealing member engaging said valve seat to permit fuel to pass from said feed inlet end and out said feed outlet end, said valve element being operatively responsive to a predetermined pressure of the returned fuel in said lateral bore for moving said valve element against said yieldable means to unseat said sealing member from its engagement with said valve seat, said valve element when operative substantially blocking the flow of fuel from said feed inlet end to said feed outlet end.

10. The fuel injection system as defined in claim 9 wherein said valve element includes an indented portion between its said end portions forming a chamber with the Wall of said longitudinal bore, said chamber being adapted to be in communication with said other lateral bore when the sealing member engages said valve seat, said valve element having a passageway extending into the other of said valve element ends and terminating therewithin at one end, the other end of said passageway communicating with said longitudinal bore, said valve element having a passage communicating between said chamber and said passageway, said feed fluid flow passing through said other lateral bore into said chamber and through said passage into said passageway and out said longitudinal bore through said feed line outlet end, said chamber being out of alignment with said other lateral bore when said valve element operatively responds to said predetermined pressure thereby disposing said valve element blockingly over said other lateral bore.

11. In a fuel injection system for an engine having a fuel tank, a pump, engine injectors, feed line means connecting said pump to said tank and said injectors for delivering fuel from said tank to said injectors, return line means connected between the engine and said tank for returning excess fuel from said injectors, the improvement comprising an overload valve means including a unitary housing having bores intersecting internally thereof, a valve element movably positioned within one said bore, said other bore having ends opening outwardly of said housing and connected Within said return line means and respectively constituting a return inlet and a therethrough, said one bore opening outwardly of said housing at a feed outlet, said housing having a feed inlet bore communicating with said one bore between said intersection of said bores and said feed outlet for the normal passage of fuel therethrough, compression spring means within said one bore between said feed outlet and said valve element for maintaining said valve element inoperative to permit fuel to pass from said feed inlet through said one bore and out said feed outlet, said valve element 10 substantially terminating the flow of fuel from said feed inlet into said one bore.

References Cited by the Examiner UNITED STATES PATENTS 2,280,140 4/1942 Wilson 15842.1 3,032,051 5/ 1962 Marette et al 13-7-87 3,043,324 7/1962 Morgan 137-87 3,094,162 6/1963, Davies 15842.1

FREDERICK L. MATTESON, JR.,, Primary Examiner.

ROBERT A. DUA, Examiner. 

1. IN A FUEL INJECTION SYSTEM FOR AN ENGINE HAVING A FUEL TANK, A PUMP ENGINE INJECTORS, FEED LINE MEANS CONNECTING SAID PUMP TO SAID TANK AND SAID INJECTORS FOR DELIVERING FUEL FROM SAID TANK TO SAID INJECTORS, RETURN LINE MEANS CONNECTED BETWEEN THE ENGINE AND SAID TANK FOR RETURNING EXCESS FUEL FROM SAID INJECTORS, THE IMPROVEMENT COMPRISING AN OVERLOAD VALVE MEANS CONNECTED TO SAID RETURN LINE MEANS AND SAID LINE MEANS BETWEEN SAID PUMP AND TANK, SAID VALVE MEANS BEING OPERABLE TO SUBSTANTIALLY TERMINATE THE FUEL FLOW THROUGH SAID FEED LINE MEANS WHEN THE PRESSURE IN SAID RETURN LINE MEANS EXCEEDS A PREDETERMINED AMOUNT. 